1. Field of the Invention
The present invention generally relates to a photographic lens, a method of manufacturing the photographic lens, and a photographic apparatus including the photographic lens. More particularly, the present invention relates to a method of manufacturing a photographic lens by which high optical performance may be secured by reducing errors caused while assembling lenses.
2. Description of the Related Art
Recently, imaging optical instruments such as digital cameras or digital camcorders using image pickup devices, such as charge coupled devices (CCD) or complementary metal-oxide semiconductors (CMOS), have been widely used. As more imaging optical instruments having improved performance (such as increases in magnification and increases in the number of pixels) become lower-priced and more lightweight, zoom lenses used in imaging optical instruments need to also have improved performance, and become lower-priced and more lightweight.
For this, a three group type zoom lens including three lens groups, respectively having negative, positive, and positive refractive power, that are sequentially arranged from an object side, has been widely used to reduce the number of lenses constituting a zoom lens and reduce an entire optical length.
However, as the magnification of an optical system increases and the size of the optical system decreases, aberrations caused by manufacturing errors or assembly errors, i.e., sensitivity to the errors, tends to increase. In addition, aberrations caused by manufacturing errors or assembly errors need to be reduced in order to obtain an optical system having excellent imaging performance with an increased number of pixels.
Thus, there is a need to prevent lens manufacturing errors and assembly errors. However, there is a limit to manufacturing and assembly error reduction. More specifically, having too small of an error margin may decrease the yield.
A method of adjusting lenses includes modifying the structure of a lens barrel or a lens housing. However, the configuration of the lens housing may become complicated when lenses are highly sensitive to spherical aberration and field curvature.